text: /*
   * Regulators driver for Maxim max8925
   *
   * Copyright (C) 2009 Marvell International Ltd.
   *      Haojian Zhuang <haojian.zhuang@marvell.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/err.h>
  #include <linux/i2c.h>
  #include <linux/platform_device.h>
  #include <linux/regulator/driver.h>
  #include <linux/regulator/machine.h>
  #include <linux/mfd/max8925.h>
  #include <linux/of.h>
  #include <linux/regulator/of_regulator.h>
  
  #define SD1_DVM_VMIN		850000
  #define SD1_DVM_VMAX		1000000
  #define SD1_DVM_STEP		50000
  #define SD1_DVM_SHIFT		5		/* SDCTL1 bit5 */
  #define SD1_DVM_EN		6		/* SDV1 bit 6 */
  
  /* bit definitions in LDO control registers */
  #define LDO_SEQ_I2C		0x7		/* Power U/D by i2c */
  #define LDO_SEQ_MASK		0x7		/* Power U/D sequence mask */
  #define LDO_SEQ_SHIFT		2		/* Power U/D sequence offset */
  #define LDO_I2C_EN		0x1		/* Enable by i2c */
  #define LDO_I2C_EN_MASK		0x1		/* Enable mask by i2c */
  #define LDO_I2C_EN_SHIFT	0		/* Enable offset by i2c */
  
  struct max8925_regulator_info {
  	struct regulator_desc	desc;
  	struct regulator_dev	*regulator;
  	struct i2c_client	*i2c;
  	struct max8925_chip	*chip;
  
  	int	vol_reg;
  	int	enable_reg;
  };
  
  static int max8925_set_voltage_sel(struct regulator_dev *rdev,
  				   unsigned int selector)
  {
  	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
  	unsigned char mask = rdev->desc->n_voltages - 1;
  
  	return max8925_set_bits(info->i2c, info->vol_reg, mask, selector);
  }
  
  static int max8925_get_voltage_sel(struct regulator_dev *rdev)
  {
  	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
  	unsigned char data, mask;
  	int ret;
  
  	ret = max8925_reg_read(info->i2c, info->vol_reg);
  	if (ret < 0)
  		return ret;
  	mask = rdev->desc->n_voltages - 1;
  	data = ret & mask;
  
  	return data;
  }
  
  static int max8925_enable(struct regulator_dev *rdev)
  {
  	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
  
  	return max8925_set_bits(info->i2c, info->enable_reg,
  				LDO_SEQ_MASK << LDO_SEQ_SHIFT |
  				LDO_I2C_EN_MASK << LDO_I2C_EN_SHIFT,
  				LDO_SEQ_I2C << LDO_SEQ_SHIFT |
  				LDO_I2C_EN << LDO_I2C_EN_SHIFT);
  }
  
  static int max8925_disable(struct regulator_dev *rdev)
  {
  	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
  
  	return max8925_set_bits(info->i2c, info->enable_reg,
  				LDO_SEQ_MASK << LDO_SEQ_SHIFT |
  				LDO_I2C_EN_MASK << LDO_I2C_EN_SHIFT,
  				LDO_SEQ_I2C << LDO_SEQ_SHIFT);
  }
  
  static int max8925_is_enabled(struct regulator_dev *rdev)
  {
  	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
  	int ldo_seq, ret;
  
  	ret = max8925_reg_read(info->i2c, info->enable_reg);
  	if (ret < 0)
  		return ret;
  	ldo_seq = (ret >> LDO_SEQ_SHIFT) & LDO_SEQ_MASK;
  	if (ldo_seq != LDO_SEQ_I2C)
  		return 1;
  	else
  		return ret & (LDO_I2C_EN_MASK << LDO_I2C_EN_SHIFT);
  }
  
  static int max8925_set_dvm_voltage(struct regulator_dev *rdev, int uV)
  {
  	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
  	unsigned char data, mask;
  
  	if (uV < SD1_DVM_VMIN || uV > SD1_DVM_VMAX)
  		return -EINVAL;
  
  	data = DIV_ROUND_UP(uV - SD1_DVM_VMIN, SD1_DVM_STEP);
  	data <<= SD1_DVM_SHIFT;
  	mask = 3 << SD1_DVM_SHIFT;
  
  	return max8925_set_bits(info->i2c, info->enable_reg, mask, data);
  }
  
  static int max8925_set_dvm_enable(struct regulator_dev *rdev)
  {
  	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
  
  	return max8925_set_bits(info->i2c, info->vol_reg, 1 << SD1_DVM_EN,
  				1 << SD1_DVM_EN);
  }
  
  static int max8925_set_dvm_disable(struct regulator_dev *rdev)
  {
  	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
  
  	return max8925_set_bits(info->i2c, info->vol_reg, 1 << SD1_DVM_EN, 0);
  }
  
  static struct regulator_ops max8925_regulator_sdv_ops = {
  	.map_voltage		= regulator_map_voltage_linear,
  	.list_voltage		= regulator_list_voltage_linear,
  	.set_voltage_sel	= max8925_set_voltage_sel,
  	.get_voltage_sel	= max8925_get_voltage_sel,
  	.enable			= max8925_enable,
  	.disable		= max8925_disable,
  	.is_enabled		= max8925_is_enabled,
  	.set_suspend_voltage	= max8925_set_dvm_voltage,
  	.set_suspend_enable	= max8925_set_dvm_enable,
  	.set_suspend_disable	= max8925_set_dvm_disable,
  };
  
  static struct regulator_ops max8925_regulator_ldo_ops = {
  	.map_voltage		= regulator_map_voltage_linear,
  	.list_voltage		= regulator_list_voltage_linear,
  	.set_voltage_sel	= max8925_set_voltage_sel,
  	.get_voltage_sel	= max8925_get_voltage_sel,
  	.enable			= max8925_enable,
  	.disable		= max8925_disable,
  	.is_enabled		= max8925_is_enabled,
  };
  
  #define MAX8925_SDV(_id, min, max, step)			\
  {								\
  	.desc	= {						\
  		.name	= "SDV" #_id,				\
  		.ops	= &max8925_regulator_sdv_ops,		\
  		.type	= REGULATOR_VOLTAGE,			\
  		.id	= MAX8925_ID_SD##_id,			\
  		.owner	= THIS_MODULE,				\
  		.n_voltages = 64,				\
  		.min_uV = min * 1000,				\
  		.uV_step = step * 1000,				\
  	},							\
  	.vol_reg	= MAX8925_SDV##_id,			\
  	.enable_reg	= MAX8925_SDCTL##_id,			\
  }
  
  #define MAX8925_LDO(_id, min, max, step)			\
  {								\
  	.desc	= {						\
  		.name	= "LDO" #_id,				\
  		.ops	= &max8925_regulator_ldo_ops,		\
  		.type	= REGULATOR_VOLTAGE,			\
  		.id	= MAX8925_ID_LDO##_id,			\
  		.owner	= THIS_MODULE,				\
  		.n_voltages = 64,				\
  		.min_uV = min * 1000,				\
  		.uV_step = step * 1000,				\
  	},							\
  	.vol_reg	= MAX8925_LDOVOUT##_id,			\
  	.enable_reg	= MAX8925_LDOCTL##_id,			\
  }
  
  #ifdef CONFIG_OF
  static struct of_regulator_match max8925_regulator_matches[] = {
  	{ .name	= "SDV1",},
  	{ .name = "SDV2",},
  	{ .name = "SDV3",},
  	{ .name = "LDO1",},
  	{ .name = "LDO2",},
  	{ .name = "LDO3",},
  	{ .name = "LDO4",},
  	{ .name = "LDO5",},
  	{ .name = "LDO6",},
  	{ .name = "LDO7",},
  	{ .name = "LDO8",},
  	{ .name = "LDO9",},
  	{ .name = "LDO10",},
  	{ .name = "LDO11",},
  	{ .name = "LDO12",},
  	{ .name = "LDO13",},
  	{ .name = "LDO14",},
  	{ .name = "LDO15",},
  	{ .name = "LDO16",},
  	{ .name = "LDO17",},
  	{ .name = "LDO18",},
  	{ .name = "LDO19",},
  	{ .name = "LDO20",},
  };
  #endif
  
  static struct max8925_regulator_info max8925_regulator_info[] = {
  	MAX8925_SDV(1, 637.5, 1425, 12.5),
  	MAX8925_SDV(2,   650, 2225,   25),
  	MAX8925_SDV(3,   750, 3900,   50),
  
  	MAX8925_LDO(1,  750, 3900, 50),
  	MAX8925_LDO(2,  650, 2250, 25),
  	MAX8925_LDO(3,  650, 2250, 25),
  	MAX8925_LDO(4,  750, 3900, 50),
  	MAX8925_LDO(5,  750, 3900, 50),
  	MAX8925_LDO(6,  750, 3900, 50),
  	MAX8925_LDO(7,  750, 3900, 50),
  	MAX8925_LDO(8,  750, 3900, 50),
  	MAX8925_LDO(9,  750, 3900, 50),
  	MAX8925_LDO(10, 750, 3900, 50),
  	MAX8925_LDO(11, 750, 3900, 50),
  	MAX8925_LDO(12, 750, 3900, 50),
  	MAX8925_LDO(13, 750, 3900, 50),
  	MAX8925_LDO(14, 750, 3900, 50),
  	MAX8925_LDO(15, 750, 3900, 50),
  	MAX8925_LDO(16, 750, 3900, 50),
  	MAX8925_LDO(17, 650, 2250, 25),
  	MAX8925_LDO(18, 650, 2250, 25),
  	MAX8925_LDO(19, 750, 3900, 50),
  	MAX8925_LDO(20, 750, 3900, 50),
  };
  
  #ifdef CONFIG_OF
  static int max8925_regulator_dt_init(struct platform_device *pdev,
  				    struct regulator_config *config,
  				    int ridx)
  {
  	struct device_node *nproot, *np;
  	int rcount;
  	nproot = of_node_get(pdev->dev.parent->of_node);
  	if (!nproot)
  		return -ENODEV;
  	np = of_find_node_by_name(nproot, "regulators");
  	if (!np) {
  		dev_err(&pdev->dev, "failed to find regulators node\n");
  		return -ENODEV;
  	}
  
  	rcount = of_regulator_match(&pdev->dev, np,
  				&max8925_regulator_matches[ridx], 1);
  	of_node_put(np);
  	if (rcount < 0)
  		return -ENODEV;
  	config->init_data =	max8925_regulator_matches[ridx].init_data;
  	config->of_node = max8925_regulator_matches[ridx].of_node;
  
  	return 0;
  }
  #else
  #define max8925_regulator_dt_init(x, y, z)	(-1)
  #endif
  
  static int max8925_regulator_probe(struct platform_device *pdev)
  {
  	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
  	struct regulator_init_data *pdata = pdev->dev.platform_data;
  	struct regulator_config config = { };
  	struct max8925_regulator_info *ri;
  	struct resource *res;
  	struct regulator_dev *rdev;
  	int i, regulator_idx;
  
  	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
  	if (!res) {
  		dev_err(&pdev->dev, "No REG resource!\n");
  		return -EINVAL;
  	}
  	for (i = 0; i < ARRAY_SIZE(max8925_regulator_info); i++) {
  		ri = &max8925_regulator_info[i];
  		if (ri->vol_reg == res->start) {
  			regulator_idx = i;
  			break;
  		}
  	}
  
  	if (i == ARRAY_SIZE(max8925_regulator_info)) {
  		dev_err(&pdev->dev, "Failed to find regulator %llu\n",
  			(unsigned long long)res->start);
  		return -EINVAL;
  	}
  	ri->i2c = chip->i2c;
  	ri->chip = chip;
  
  	config.dev = &pdev->dev;
  	config.driver_data = ri;
  
  	if (max8925_regulator_dt_init(pdev, &config, regulator_idx))
  		if (pdata)
  			config.init_data = pdata;
  
  	rdev = regulator_register(&ri->desc, &config);
  	if (IS_ERR(rdev)) {
  		dev_err(&pdev->dev, "failed to register regulator %s\n",
  				ri->desc.name);
  		return PTR_ERR(rdev);
  	}
  
  	platform_set_drvdata(pdev, rdev);
  	return 0;
  }
  
  static int max8925_regulator_remove(struct platform_device *pdev)
  {
  	struct regulator_dev *rdev = platform_get_drvdata(pdev);
  
  	platform_set_drvdata(pdev, NULL);
  	regulator_unregister(rdev);
  
  	return 0;
  }
  
  static struct platform_driver max8925_regulator_driver = {
  	.driver		= {
  		.name	= "max8925-regulator",
  		.owner	= THIS_MODULE,
  	},
  	.probe		= max8925_regulator_probe,
  	.remove		= max8925_regulator_remove,
  };
  
  static int __init max8925_regulator_init(void)
  {
  	return platform_driver_register(&max8925_regulator_driver);
  }
  subsys_initcall(max8925_regulator_init);
  
  static void __exit max8925_regulator_exit(void)
  {
  	platform_driver_unregister(&max8925_regulator_driver);
  }
  module_exit(max8925_regulator_exit);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
  MODULE_DESCRIPTION("Regulator Driver for Maxim 8925 PMIC");
  MODULE_ALIAS("platform:max8925-regulator");
  